Analysis of Hull Forces and Changes in Paddle Thrust during Passage of a Ship Passing a Spur Dike
The bundling effect of the super dike will cause an increase in the flow velocity of the river outside the dam head,which will have a large impact on the navigational resistance and propeller thrust of the passing ship.In this paper,the volumetric force method is used to establish a ship-paddle-rudder integrated self-propelled model.Based on the RANS equation,the Realizable k-εturbulence model is combined to numerically simulate the ship force and propeller thrust during the process of ship crossing the super dike.The simulation results are also compared with the experimental data to prove the rationality of the numerical simulation method.Then,the river flow velocity and ship speed are used as the variation parameters for numerical analysis.The study shows that the variation of longitudinal force(hull resistance),transverse force and bow moment of the ship gradually decreases with the increase of the ship speed,and the variation of transverse force shows a double-peaked curve.The distribution of the companion flow in front of the propeller is not symmetrical with respect to the mid-longitudinal profile of the ship,but favors the low velocity return area behind the super dike.The high companion flow area when the ship is downstream of the super dike is more concentrated near the mid-longitudinal profile of the ship.
Spur dikeHydrodynamic characteristicsBody force methodShip-propeller-rudder integration